This invention relates to a vehicle driveshaft assembly and a method for its manufacture. More specifically, this invention relates to a driveshaft assembly including a driveshaft tube having a pair of opposed lug cars formed integrally therein that are configured to support a universal joint assembly therein. The universal joint assembly includes a journal and bearing carrier that is formed from a rectangular tube section or two separate stampings and a pair of bearing supports that are inserted into the journal and bearing carrier. The invention also relates to a method of manufacturing such a driveshaft assembly.
In most land vehicles in use today, a drive train assembly is provided for transmitting rotational power from an output shaft of an transmission to an input shaft of an axle assembly so as to rotatably drive one or more wheels of the vehicle. To accomplish this, a typical vehicular drive train assembly includes a hollow cylindrical driveshaft tube. A first universal joint is connected between the output shaft of the transmission and a first end of the driveshaft tube, while a second universal joint is connected between a second end of the driveshaft tube and the input shaft of the axle assembly. The universal joints provide a rotational driving connection from the output shaft of the transmission through the driveshaft tube to the input shaft of the axle assembly, while accommodating a limited amount of angular misalignment between the rotational axes of these three shafts.
A typical universal joint includes a cross having a central body portion with four cylindrical trunnions extending outwardly therefrom. The trunnions are oriented in a single plane and extend at right angles relative to one another. A hollow cylindrical bearing cup having a cylindrical outer wall and a circular end wall is mounted on the end of each of the trunnions. A bearing structure, such as a plurality of needle bearings or roller bearings, is provided between the trunnion and the associated bearing cup to facilitate relative rotational movement therebetween. The bearing cups that are mounted on a first opposed pair of the trunnions can be connected to a first yoke secured to a first component of the drive train assembly, while the bearing cups mounted on a second opposed pair of the trunnions can be connected to a second yoke secured to a second component of the drive shaft assembly.
Traditionally, the ends of the driveshaft tube are connected to the universal joints by respective tube yokes. A typical tube yoke includes a sleeve portion that is sized to be press fit within the end of the driveshaft tube. The sleeve portion of the tube yoke is usually permanently secured to the end of the driveshaft tube, such as by welding, adhesives, and the like. The tube yoke further includes a yoke portion having a pair of opposed arms extending therefrom. The opposed arms of the yoke portion are adapted to receive the opposed bearing cups provided on the universal joint cross in the manner described above. Although this general structure has been in common use for many years, it would be desirable to provide an improved structure for a driveshaft assembly that is simpler and less expensive than known structures.